Hi

had my first service at ford dealership they saying my brake fluid have have 4% water what does it mean why is there water is it a  sign of something

 Brake fluid will over time attract water, 4% is a lot so you should lol at having it changed. Had mine done on my ST as its recommended at 24 months think it was only £35

3 minutes ago, MarksST said:

 Brake fluid will over time attract water, 4% is a lot so you should lol at having it changed. Had mine done on my ST as its recommended at 24 months think it was only £35

Im going to have it changed tomorrow where is good place ? Halfords autocentre?

3 minutes ago, Patrico777 said:

Im going to have it changed tomorrow where is good place ? Halfords autocentre?

Go to somewhere you trust to do a good job first time round without any hassle or issue.

Err, it is a sign of water in the brake fluid and not much else. Well apart from old brake fluid probably; it is probably more likely if mess around with it a lot.

it does absorb water over time and having absorbed water the boiling point goes down and that isn't what you want.
 

The only thing Halfrauds Autocentre is good for is driving past.  I wouldn't trust them to fix a pedal car, let alone a real one.

So I go to my mate garage then buy the brake fluid and he change it for me I also need my discs changed should I buy drilled once ?

His garage will probably bulk buy fluid cheaply?

I wouldn't bother with drilled discs, they can crack between the holes with the heat cycles.

Err, it is a sign of water in the brake fluid and not much else. Well apart from old brake fluid probably; it is probably more likely if mess around with it a lot.

it does absorb water over time and having absorbed water the boiling point goes down and that isn't what you want.

 

Brake fluid is hygroscopic so will attract water over time affecting it's compression ratios.

Water is non-compressable and therefore causes uneven pressure transmission throughout a fluid.

Sent from my SM-G930F

3 hours ago, Stoney871 said:

Brake fluid is hygroscopic so will attract water over time affecting it's compression ratios.

Water is non-compressable and therefore causes uneven pressure transmission throughout a fluid.

Sent from my SM-G930F

I get it changed tomorrow then deffo which brake fluid is good?

3 hours ago, TomsFocus said:

His garage will probably bulk buy fluid cheaply?

I wouldn't bother with drilled discs, they can crack between the holes with the heat cycles.

They made for heat protection and they will crack ?

Cheap drilled discs are for show, not much else imo.

Brake Fluid should be done every 2 years but is not included in a standard service, so the previous owners obviously hasn't done it for a while.

4 minutes ago, alexp999 said:

Cheap drilled discs are for show, not much else imo.

Brake Fluid should be done every 2 years but is not included in a standard service, so the previous owners obviously hasn't done it for a while.

How much are better drilled discs ??? 

Honestly, drilled discs wont make any difference on the road in an ST150.  I have seen a few crack, though I admit most were after track use!

Go for a decent brand of 'normal' discs imo, I stick with Pagid myself.

5 hours ago, Stoney871 said:

Brake fluid is hygroscopic so will attract water over time affecting it's compression ratios.

Water is non-compressable and therefore causes uneven pressure transmission throughout a fluid.

Sent from my SM-G930F

Hydraulic fluid is used in the braking system because it's virtually uncompressable, it's that property that transmits the pressure and makes the brakes work, any water in it would lower the boiling point of the fluid, if the fluid boils gas will form in the fluid causing a spongy feeling when you press the pedal, same as having air in the system.

8 hours ago, Patrico777 said:

How much are better drilled discs ??? 

 

8 hours ago, TomsFocus said:

Honestly, drilled discs wont make any difference on the road in an ST150.  I have seen a few crack, though I admit most were after track use!

Go for a decent brand of 'normal' discs imo, I stick with Pagid myself.

Just go with either standard vented discs or the grooved ones, as some have already said, drilled discs can crack, to prevent this the drilled holes need to be countersunk on each side, fine on the front face of the disc but rather difficult inside the vents!

Personally I would just go with some standard vented discs and upgrade the brake pads to some green stuff pads, maybe also look at braided lines, unless you are on the track there isn't too much reason to need to upgrade the discs as I doubt you will need to dissipate heat due to brake fade on the road.

And yes brake fluid absorbs water over time, most of the brake fluid is in the reservoir so a garage will usually just change that part, to get all of the old fluid out you would need to get the brake calipers bled - this would also help with performance if there is any spongyness in the pedel.

Another thing to mention is that fitting grooved discs will increase the wear of the brake pads - it's basically having the pads pushed up against a cheese grater!

2 hours ago, m1tch said:

And yes brake fluid absorbs water over time, most of the brake fluid is in the reservoir so a garage will usually just change that part, to get all of the old fluid out you would need to get the brake calipers bled - this would also help with performance if there is any spongyness in the pedal.

Which garage are you using??  A brake fluid change will include bleeding all the old fluid out through the bleed nipples!

1 hour ago, TomsFocus said:

Which garage are you using??  A brake fluid change will include bleeding all the old fluid out through the bleed nipples!

Will it not be better change brake fluid and discs and the same time? 

17 hours ago, GaryPL said:

The only thing Halfrauds Autocentre is good for is driving past.  I wouldn't trust them to fix a pedal car, let alone a real one.

Why not ?

3 hours ago, Patrico777 said:

Why not ?

Uh. I'm warning people off of Halfords Autocentre because they're fantastic and complete every job to exacting standards of perfection?

I used Halfords once. Once being the operative word.

1 hour ago, Bobr said:

I used Halfords once. Once being the operative word.

I used them 'once' too. Once to get a problem fixed and then 2 more times to get the same problem fixed.  Let's just say that Vauxhall fixed the same problem for 30 minutes labour (including diagnostics) and a £3.00 part.

8 minutes ago, GaryPL said:

I used them 'once' too. Once to get a problem fixed and then 2 more times to get the same problem fixed.  Let's just say that Vauxhall fixed the same problem for 30 minutes labour (including diagnostics) and a £3.00 part.

I once saw them trying to change somebody's rear wiper blade for 20 minutes, they still didn't manage it.

Guess I will leave halfords, lol and go somewhere als would it be better to change brake fluid when changing discs or it does not matter ?

If you have 4% water in the brake fluid it really does want changing.   If you are going to have new disks and pads it makes sense to get it all done at the same time.